Glass-ceramics are widely used in various industries. The glass-ceramics are mainly used for manufacturing tiles due to properties such as, but not limited to, high strength, toughness, translucency or opacity, low or even negative thermal expansion, high temperature stability and high chemical durability.
Generally, the glass-ceramics are produced using a two steps process. In first step, a glass is produced by a glass manufacturing process using different types of raw materials. During the second step, the glass is melted and cast into a mold or shaped using any techniques known to those ordinarily skilled in the art. The molten glass is cooled down and thereafter reheated to partly crystallize the glass during the second step.
An alternative method for manufacturing glass-ceramics includes sintering and crystallizing glass particles of suitable composition. Sintering temperature needs to be adjusted well above crystallization temperature and high heating rates are required to force the glass to sinter before extensive crystallization. For such adjustment, secondary glasses such as soda-lime scraps or recycled pharmaceutical borosilicate glasses are used as sintering aids. Alternatively, nucleation agents are typically added for aiding and controlling the crystallization process. The high heating rates required to force the glass to sinter before extensive crystallization consumes high amount of energy. Further, the glass-ceramics produced using the conventional method exhibit only few desired mechanical and chemical properties as the amount of crystal phases in the glass-ceramics is low. Moreover, the amount of natural raw materials used in the conventional methods for preparing glass-ceramic is also high.
Additionally, glass wastes are immobilized by disposal in land-fills or immobilized in cement industries. Economic justification for capital and operational costs of implementing procedures for disposal of glass waste tends to be very high.
Therefore, there is a need to develop a method for manufacturing glass-ceramics, which is environment friendly, cost effective and has superior mechanical and chemical properties.